Previous work with sexual and parthenogenetic Drosophila mercatorum revealed a syndrome known as abnormal abdomen (aa) that involves at least six loci on four chromosomes. Several aging effects are associated with this polygenic complex, including: 1) a prolongation of pre-adult life, 2) earlier ovarian maturation, 3) earlier onset of egg laying, 4) an age-specific fecundity schedule that peaks early and then plateaus, 5) an age-specific viability schedule that drops off sharply after about two weeks of age, considerably shortening adult life span, and 6) a blockage of the normal development of female sexual receptivity and of the male testes. Some of these phenotypic expressions may be related to juvenile hormone. Parthenogenesis will be used to breed truly isogenic aa, non-aa and various hybrid strains whose aging and life history characteristics will then be carefully measured to quantify the previously noted aging effects and perhaps to uncover additional effects. The unique features of the parthenogenetic/sexual reproductive system of D. mercatorum will then be utilized to illucidate in detail the genetic basis of the aging effects. Finally, by taking advantage of the simplified field situation that exists for the Kamuela population of D. mercatorum and recently perfected aging measures that can be applied to wild-caught flies, field studies will be performed to see if the aging effects also occur in nature and to determine how the aging effects relate to the population structure and ecology of the flies in nature.